Apparatus for the control of railway car retarders



Nov. 26, 1935. .1. w. LIVINGSTON 2,022,086

APPARATUS FOR THE CONTROL OF RAILWAY CAR RETARDERS F11ed Feb. 11, 1952Cil ' tarder A1 are moved toward the right,

Patented Nov. 26, 1935 APPARATUS. Eon THE-ooN'rnoLoF' RAILWAY CARBETARDERS- John W'. Livingston, Wilkinsburg, Pa., assigner to The UnionSwitch'v & Signal Company,

Swissvale, Pa., a corporation of Pennsylvania Application February 11,1932, SerialNm 592,262

7 Claims.

My invention relates to apparatus for the control of railway carretarders, and particularly to apparatus for controlling iiuid pressureoperated car retarders,

One object of my invention is to provide means for securing` severaldifferent pressures in the actuating mechanism with a minimum number ofline wires between the mechanism and its con troller lever.

Another object of my invention is to provide means whereby severalretarders may be operated either separatelyY by. individual controllerlevers or simultaneously by a master controller lever. e

I will describe one form ofapparatus embodying my invention, and willthen point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic View showing one form ofapparatus embodying my invention.

While my invention may be applied to the control of any desired numberof car retarders, for purpose of illustration I have shown it applied tothe control of only two ca-r retarders in the drawing, this number beingdeemed suicient for a clear understanding of my invention. These two carretarders, which are designated in their entirety by the referencecharacters A1 and A2, respectively, are similar, and each comprises twobraking bars 2 and 3, located on opposite sides of, and extendingparallel with, one track rail I of a stretch B of railway track, and twosimilar braking bars 211 and 311, located on opposite sides of, andextending parallel with, the other track rail Ia of the stretch B. v

In accordance with my invention means are provided for controlling thetwo car retarders A1 and A2 either separately by individual controllerslevers L1 orL2, or jointly by a master controller lever LM. The meansfor controlling each retarder by its individual lever are similar, andit is believed, therefore, that a clearunderstanding of both means maybe had from a description of only one.

Referring particularlyk to the means for separately controlling'y theretarded A1, this means includes a iluid pressure motor M1 comprising acylinder li containing a reciprocable piston 5 which is attached to .apiston rod 5a. The braking bars 2', 3, 211 and 311 are operativelyconnected with the piston rod 5e of motor M1 through a suitable'linkage`including a lever 6 pivotedV at 6a. When piston 5 of motor M1 moves toits lefthand position, braking barsi3 and 311 of car reandbraking bars 2and 211 are moved toward the left, and the braking bars then occupytheir ineffective or non-braking'positions, as shown in the drawing.When piston 5 is moved to its righthand position, however, the brakingbars are each 5 moved toward the associated krail to their effective orbraking positions in which they engage the sides Vof the wheels ofa'railway vehicle traversing rails I and la.

Motor M1V is controlled by three magnet valves 10 D1, `E1 and F1. TheseValves are similar and each comprises a valve stem l, biased to an upperposition by a spring 8- and provided with an armature 9 and a windingI0. When valve D1 is energized, valve stem l of this valve moves 15downwardly against the bias exerted by spring 8, anda .pipe II whichcommunicates with the left-hand or application end of motor M1, is thenconnected with a pipe I2 which is constantly supplied with fluid.pressure, usually air, 20 from a vsuitable source not shown in thedrawing. When-valve D1 is deenergized, however, valve steml'l of thisvalve is moved upwardly by spring 8,- and. pipev II is then disconnectedfrom pipe l2. When valve'El is energized,`valve stem 25 'I of this valvemoves downwardly, and pipe II is then connected with atmosphere througha pipe I3 and aport I4, but when valve E1 is deenergized, pipe II isdisconnected from atmos' phere and a pipe right-hand or restoring end ofmotor M1, is vented to atmosphere through port Ill;k Whenvalve F1'isenergized, valvestem 1 of this valve moves downwardly and connects pipevI5 with pipe I2,

but when valve F1 is deenergized, pipe I5 is dis- 35- connected fromrpipe I2..v It will be apparent, therefore, that when valve .D1 isenergized, the application end of motor M1 is supplied with iiuidpressure, and when valve F1 is energized, the

restoring end of motor IM1 supplied with. iiuid 4o pressure.Furthermore, when valve E1 is energized, the aplication end of motor M1is vented to atmosphere, and when` valve E1 is deenergized, therestoring, end of -motor M1 is .ventedv to atmosphere. v v e i K ValvesD1, E1 and F1 are controlled in part by a plurality of v'similarpressure responsive devices each designated by the reference characterKwith a-distinguishing exponent and subscript. Referring to the pressureresponsive device Kim-2, for example, this device comprises a `Bourdon4tube I6, connectedby means of a pipe I1 with the application end ofmotor'ML- and hence subjected to the pressurein the applicavtionend-"oiA motor M1. The Bourdontube's AIt 5:5?

I5 which communicates with the 30 each control two contacts |8-I81 and|8-|8b, and are arranged to operate in succession as the pressure in theapplication end of motor M1 increases. For example, for a pressure belowten pounds per square inch, all contacts IS-Ia of both of these devicesare closed. If the pressure exceeds ten pounds per square inch, however,contact lil-i8a of device K110r2 opens, and if the pressure exceedstwenty pounds per square inch, contact |8-l8b of device K1N-20 closes.In similar manner, the pressure responsive rdevice Kfm-50 is adjusted toopen its contact l|8`|8a at forty pounds per square inch, and to closeits contact l8-I8b at ifty pounds per squareinch. Of course, thesespecic pressures are not essential but are only mentioned for purposesof explanation.

The valves E1 and F1 are also controlled in part by a contact G1 which,inturn, is controlledl in accordance with the position of piston 5 ofmotor M1 in such manner that this contact will beclosed at all timesexcept when the piston is moved Vto its extreme left-hand position inwhich the braking bars occupy their ineffective or non-brakingpositions, as shownin the drawing. Y

The valves D1, E1 and F1 are further controlled by the lever L1 which,as here shown, is capable of assuming five positions indicated by dottedlines in the drawing. The first position is designated R, and is theposition in which the lever is placed when it is desired to restore thebraking bars of the car retarder A1 to their ineiective or non-brakingpositions. The second position of the lever L1 is designated N, and isthe normal position, that is, the position in which the lever L isplaced when no control ofthe retarder by the lever L1 is desired. Thethird and fourth positions of the lever L1 are designated P10-2 andF40-5, respectively, meaning that when the lever is in position P1040 apressure of between ten and twenty pounds per square inch will bemaintained in the left-hand, or application end, of motor M1, and whenthe lever is in the position F40-50, a pressure of between fortyV andfty pounds per square inch will be maintained in the application end ofmotor M1. The last position of the lever L1 is designated P110; when thelever is in this position the full available pressure will be admittedto the left-hand end of the motor, it being assumed that the fullavailable pressure is eighty pounds per square inch. Y

Lever L1 controls a plurality of contacts 20 to 32, inclusive, adjacenteach of which is placed a letter or letters which correspond to thelever position or positions for which the corresponding contact isclosed. For example, contact 2G is closed only when lever L1 occupiesits N position. Similarly, contact 2| is closed in the P10-211 positionof the lever, the F40-50 position of the lever, or any positionintermediate these two positions.

Lever L1 will usually be located at a point remote from the brakingapparatus, as in the control cabin of a classification yardcar retardersystem, and will be connected with the braking apparatus by means ofline wires extending from the control cabin to the braking apparatus.

As shown in the drawing, lever L1 occupies its normal position, and allcircuits leading to the retarder actuating apparatus are therefore open.The valves D1, E1 and F1 are therefore all deenergized, so that thesupply of fluidpressure to both ends of cylinder 4 of motor M1 is cutoff, and the right-hand end of cylinder 4 isvented to atmosphere. Thecontacts IB-lb of the pressure responsive devices Kim-20 `and VK14050are both open, and the contacts |8|8a are both closed. Piston 5 of motorM1 occupies its extreme left-hand position, and the braking bars of thecar retarder A1 therefore occupy their ineffective or non-brakingpositions. Since piston 5 of motor M1 occupies its extreme left-handposition, contact G1 is open. y

In explaining the operation of the apparatus thus far described as awhole, I will rst assume that the operator desires to apply a pressureof between ten and twenty pounds per square inch to theapplication endof motor M1 to cause the braking bars of the car retarder A1 to exert acorresponding pressure on the wheels of a passing car. P11-2, whereupona circuit for the application valve D1 becomes closed, which circuitpasses from a suitable source of current, here shown as a battery H,through wire 34, contact 24 of lever L1, wires 35, 36 and 31, contact 28of lever L1, line wire 38, contact |8|8a of pressure responsive deviceK1N-20, wire 39, winding I0 of valve D1, line wire 4|, wire 42, contact2| of lever L1, and wires 43 and 44 back to battery I-I. 'I'heapplication valve D1 therefore becomes energized and admits fluidpressure to the application end of motor lM1 until the pressure reachesten pounds per square inch, at which time contact lli-|831 of pressureresponsive device Kim-2 opens and interrupts the circuit just traced forvalve D1, so that this valve again becomes deenergized. The appliedpressure is, however, retained in the application end of motor M1. Ifthe pressure of the application end of motor M1 exceeds twenty poundsper square inch for any reason, contact |8-I8b of pressure responsivedevice Kilo-2 will become closed and will complete a circuit for theexhaust valve E1 which passes from battery I-I through wire 34, contact24 of lever L1, wires 35, 36 and 31, contact 28 of lever L1, line wire38, contact Iii-I8b of pressure responsive device Kim-2, wire 45,winding I0 of valve E1, wires 46 and 4l, contact G1, wire 48, line wire4|, wire 4Z, contact 2| of lever L1, and wires 43 and 44 back to batteryH. The current iiowing in this circuit will energize the exhaust valveE1, and this valve will therefore operate to exhaust fluid from theapplication end of the motor M1 until the pressure again decreases totwenty pounds per square inch, whereupon contact Iii-|81 will open andwinding lil of the exhaust valve E1 will again become deenergized. Y

If, now, the operator desires to increase the pressure in theapplication end of motor M1 to between forty and fty pounds per squareinch to increase the braking effect of the car retarder A1, he moveslever L1 to its P10-50 position. The application valve D1 then becomesenergized by virtue of a circuit which passes from battery H throughwire 34, contact 24 of lever L1, wires 35, 3b,` 3l and 49, contact 29 oflever L1, line wire ,50, wire 5|, an asymmetric unit J1 in its lowresistance direction, wire 53, contact `l---la of pressure Yresponsivedevice Kim-50, wires 54 and 39, winding l0 of application valve D1, linewire 4|, wire 42, contact 2| of lever L1, and wires 43 and 44 back tobattery H. The application valve D1 remains energized under theseconditions until the pressure in the4 application end of motor M1reaches forty pounds per square inch, whereupon the circuit just tracedfor this valve is opened at'contact I8*|8a of pressure responsive deviceX-50. If the pressure in the application end of motor M1 exceeds fiftypounds per square inch for any reason, exhaust valve E1 To do this, hemoves lever L1 to position operation of the apparatus including thelever L2 will become energized, and will exhaust fluid from the motor`until thepressure again decreases to fty pounds per squareinch, thecircuit for the exhaust valve under these conditions being from batteryH through wire 34, contact 24 of lever L1, Wires 35, 36, 31 and 49,contact 29 of lever L1, line Wire 50, wire 5|,asymmetric unit J1 in itslow resistance direction, Wire 53, contact lil-E81J of pressureresponsive device Kfm-5, wires 55 and 45, winding I0 of `exhaust valveE1, wires 45 and 41, contact G1, wire 48, line wire 4l, wire 42, contact2l of lever L, and wires 43 and 44V back to battery H.

If the operator desires to admit the full available pressure to theapplication end of motor M1, he moves lever L1 to position P30. Acircuit for the application valve D1 is then closed which may be tracedfrom battery H through Wires 34 and 55, contact 25 of lever L1, Wires 58and 42, line `vvire 4|, winding I3 of valve D1, wires 39, 54 and 53, anasymmetric unit K1 in its low resistance direction, wire 6l, line wire50, contact 29 of lever L1, wires 49, 31, 36 and 35, contact 23 of leverL1, and wire 44 back to battery H. This circuit does not include any ofthe contacts of the pressure VJtracing the sequence of operation indetail.

In order to restore the braking bars of the car retarder A1 to theirineffective or non-braking positions, the operator places lever L1 inits R or restore position. When the lever occupies this position,circuits are completed for both the exhaust valve E1 and the restoringvalve F1, so that both of these valves now' become energized. Thecircuit for the exhaust valve E1 passes from battery H through wires .34and 55,V contact25 of lever L1, wire 315, contact 21 of lever L1, lineWire 62, an asymmetric unit O1 in lits low resistance direction, Wire45, winding it of valve E1, wires and 41, contact G1, wire 48, line wire4i, wires 64 and 55, contact 32 of lever L1, and wire 44 back to batteryH. The circuit for valve F1 passes from battery H through wires 34 and56, Contact 25 of lever L1, Wire 36, contact 21 of lever L1,line wire52, wire S6, winding lli of valve F1, Wire 41, contact G1, Wire 48, lineWire 4l, wires 64 and 55, contact 22 of lever L1, and wire 44 back tobattery H. The energization of the exhaust valve E1 vents to atmospherethe fluid pressure Which was previously supplied to the application endcf motor M1, While the energization ofthe restoring valve F1 admitsfluid pressure lto the restoring end of the motor. Piston 5 of mo-tor M1therefore now moves to its extreme left-hand position to restore thebraking bars to their ineifective or non-,braking positionsWhem piston 5reaches its extreme left-hand position, Contact G1 opens and interruptsthe circuits which were previously f closed for valves E1 and F1, thusdeenergizing theservalves. Lever L1 may then be restored to its normalor N position, and when this is do-ne,

all parts will occupy their normal positions in Y for separatelycontrolling the car retarder A2, is similar in all respects to theapparatus including the lever L1 for controlling the car retarder A1,and itis believed, therefore, that it will be readily understood fromthe foregoing, and from an inspection of the drawing, without describingit in detail.

Before entering into a detailed description of the control of theretarders A1 and A2 bythe master lever LM, it should be pointed out thatthis lever is similar to the levers L1 and L2 with the exception thatthe lever LM is not provided with any contacts which are closed when thelever occupies its N position. It should also be pointed out that inorder to eiect the joint control of the car retarders by the masterlever, it is necessary that the individual levers occupy their normalpositions in which the associated contacts 24, 353, 3i and 32 areclosed.

Assuming now that the levers L1 and L2 both occupy their normalpositions, as shown in the drawing, and that the operator wishes tocause a pressure of between ten and twenty pounds per square inch to besimultaneously supplied to the application ends of both motors M1 andM2, he moves lever LM to its P10-2 position. A circuit for theapplication valve D1 will then be closed which passes from battery Hthrough wires 8l and 82, contact 24 of lever LM, wires fit, 81 and 653,contact 28 of lever LM, wires 69 and 19, contact 3l of lever L1, wire12, line wire 38, contact iii-i811 of pressure responsive device Kr20,Wire 39, winding l0 of valve D1, line Wire 4i, wire E4, contact 20 oflever L1, wires 13 and 14, contact ZI of lever LM, and wires 19 and 8Uback to battery H. At the same time, a circuit for the application valveD2 will also be closed, this latter circuit passing from battery Hthrough wires 3l and 82, contact 24 of lever LM, wires 6G, E51 and @8,contact 2B of lever LM, wire 59, contact 3i of lever L2, line Wire 15,contact iii-181 of pressure responsive device K210-20, Wire 16, windingl@ of valve D2, line wire 9|, Wires 11 and 13, contact 2S of lever L2,wire 14, contact 2l of lever LM, and wires 19 and 80 back to battery H.The valves D1 and D2 will therefore now both become energized, so thatthe braking bars of both retardersV A1 and A2 will be simultaneouslymoved toward their braking positions. When the pressure in theapplication end of motor M1 reaches ten pounds per square inch, contactrIiii231 of pressure responsive device K1 111-20 will open and willdeenergize valve D1, and if the pressure exceeds twenty pounds persquareinch, exhaust valve E1 will then become energized, the circuit forthe valve E1 under these conditions passing from battery H through wires8| and 82, contact 24 of lever LM, Wires 55, 61 and E8, contact 2S oflever LM,

wires 69 and 13, contact Si of lever L1, wire 12,

line wire 38, contact |8--i811 of pressure responsive device 31110-20,wire 45, winding it of valve E1,'wires 48 and 41, contact G1, wire 48,line wire 4 I, wire 64, contact 20 of lever L1, Wires 13 and 14, contact2i of lever LM, and wires 19 and 80 back to battery H. Similarly, whenthe pressure in the application end of motor M2 reaches tenV pounds persquare inch, contact l8-l8a of pressure responsive device H2M-2 willopen and will deenergize valve D2, and'if the pressure exceeds twentypounds per square inch, contact l8--l8b Vof pressure responsive deviceK2111-20 will become closed and will ycomplete a circuit for the exhaustvalve E2 which passes from battery H through wires 8| and 82', Contact24 of lever LM, Wires 66, 61 and 68, contact 28 of lever LM, Wire 69,contact 3| of lever L2, line Wire 15, contact |8|8b of pressureresponsive device K2102, wire 83, winding i8 of valve E2, Wires 84 and65, contact G2, wire line Wire 9|, Wires 11 and 18, Contact 28 of leverL2, wire 14, contact 2| of lever LM, and Wires 19 and 89 back to batteryH.

If, when the levers L1 and L2 are still in their normal positions, leverLM is moved to its P10-50 positions to increase the pressure in theapplication ends o the motors M1 and M2, valves D1 and D2 will bothbecome energized and will remain energized until the pressure in theapplication end of the associated motor reaches forty pounds per squareinch. The circuit for valve D1 under these conditions passes frombattery H through wires.8| and 82, contact 24 of lever LM, Wires 66, 61and 68, contact 29 of lever LM, wires 81 and 88, Contact 32 of lever L1,Wire 89, line Wire 56, wire 5i, asymmetric unit J1 in its loW resistancedirection, Wire 53, Contact |8|8a of pressure responsive device Kfm-50,Wires 54 and 39, winding |9 of valve D1, line Wire 4| Wire 64, contact29 of lever L1, wires 13 and 14, contact 2| of lever LM, and wires 19and 68 back to battery H. The circuit for valve D2 under theseconditions passes from battery H through Wires 8| and 82, contact 24 oflever LM, w'ires 66, 61 and 68, contact 29 of lever LM, Wire 81, contact32 of lever I?, line Wire 96, Wire |65, asymmetric unit J2 in its loWresistance direction, contact |8|82 of pressure responsive deviceK210r50, wires 92 and 16, Winding |9 of valve D2, line wire 9|, Wires 11and 18, contact 20 of lever L2, Wire 14, contact 2| of lever LM, andWires 19 and 88 back to battery H. I f the pressure in the applicationend of motor M1 now exceedsiifty pounds per Square inch for any reason,the exhaust valve E1 will become energized, the circuit for this valvebeing from battery H through Wires 8| and 82, contact 24 of lever LM,Wires 65, 61l and 68, contact 29 of lever LM, Wires 81 andY 88, contact32 of lever L1, Wire 89, line Wire 58, wire 5|, asymmetric unit J1 inits low resistance direction, Wire 53, contact |8|8b of pressureresponsive device Kfm-50, Wires 55 and 45, winding ID of valve E1, Wires46 and 41, contact G1, Wire 48, line Wire 4|, Wire 64, Contact 28 oflever L1, Wires 13 and 14, contact 2| of lever LM, and Wires 19 and 88back to battery H. In similar manner, if the pressure in the applicationend of motor M2 now exceeds fty pounds per square inch, the exhaustvalve E2 Will become energized over a circuit which passes from batteryH through Wires 8| and 82, contact 24 of lever LM, Wires 66, 61 and 68,contact 29 of lever LM, Wire 81, contact 32 of lever L2, line Wire 98,Wire |05, asymmetric unit J2 in its low resistance direction, contactiii-|81 of pressure responsive device K240511, Wire 83, winding I9 ofvalve E2, wires 84 and S5, contact G2, Wire 86, line Wire 9|, Wires 11and 18, contact 28 of lever L2, Wire 14, contact 2| of lever LM, andWires 19 and 86 back to battery H.

If, with the levers L1 and L2 still in their normal positions, lever LMis moved to its P20 position, full line pressure will be admitted to theapplication end of both motors M1 and M2, the valve D1 being energizedunder these conditions over a circuit which passes frombattery H throughwires 8l, 82, 93 and 94, contact 26 of lever LM, wires 95, 14 and 13,contact 2|] of lever L1, Wire 64, line wire 4|, Winding I9 of the valveD1, Wires 39, 54 and 59, asymmetric unit K1 in its 10W vresistancedirection,v Wire 6|, line Wire 50, wire 89, contact32V of lever L1,Wires- 88 and 81, contact 29 of lever LM, Wires 68, 61 and 66, contact23 of lever LM, and. wires 19 and 89 back to battery H; and the valve D2being energized over a circuit which passes from battery :5v H throughwires 8|, 82, 93 and 94, contact 26 of lever LM, Wires and 14, contact28 of lever L2, Wires 18 and 11, line Wire 9|, Winding |8'of valve D2,wires 16 and 92, asymmetric unit K2 in' its loW resistance direction,line Wire 96, con- 10 tact 32 of lever L2, wire 81, contact 29 of leverLM, Wires 68, 61 and 66, contact 23 of lever LM,

and Wires 19 and 80 back to battery H.

Assuming now that the braking bars of both car retarders are in theirbraking positions, and 15 that the operator Wishes to simultaneouslyrestore them to their ineiective or nonbraking positions, he placeslever LM in its R position. Under these conditions, the valves E1, F1,E2 and F2 Will all become energized. The circuit for 20 Valve E1 passesfrom battery H through wires 8|, 82 and 93, contact 25 of lever LM, Wire61', contact 21 of lever LM, Wires 99 and |69, contact 38 of leverL1,Wire line Wire 62, asymmetric unit O1 in its loW resistance direction,Wire 45, 25 Winding l0 of valve E1, Wires 46 and 41, contact G1, wire48, line Wire 4|, wire 64, contact 29 of lever L1, Wires 13, 14 and |62,contact 22 of lever LM, and Wires 19 and 86 back to battery H. Thecircuit for valve F1 passes from battery H through 30 Wires 8|, 82 and93, contact 25 of lever LM, wire 61, contact 21 of lever LM, Wires 99and |88, contact 38 of lever L1, Wire |6|, line Wire 62, Wire 66,Winding I!) of valve F1, Wire 41, contact G1, Wire 48, line Wire 4|,Wire 64, contact 2i) of lever 35 L1, Wires 13, 14 and |92, contact 22 oflever LM, and Wires 19 and 88 back to battery H. The circuit for ValveE2 passes from battery H through Wires 8|, 82 and 93, contact 25 oflever LM, Wire 61, contact 21 of lever LM, Wire 99, contact 38 of 40lever L2, line Wire |83, asymmetric unit O2 in its low resistancedirection, Wire 83, Winding i8 of valve E2, Wires 84 and 85, contact G2,Wire 88, line wire 9|, Wires 11 and 18, contact 20 of lever L2, wire 14and |62, contact 22 of lever LM, and. Wires 45 19 and 80 back to batteryH. The circuit for valve F2 under these conditions passes from battery Hthrough wires 8| 82 and 93, contact 25 of lever LM, Wire 61, contact 271of lever LM, Wire 99, contact 38 of lever L2, line Wire |63, Wire |84,50 Winding I of valve F2, wire 85, contact G2, Wire 86, line Wire 9|,Wires 11 and 18, Contact 28 of lever L2, Wires 14 and |82, contact 22 oflever LM, and Wires 19 and 88 back tol battery H. The energization ofthe valve E1 exhausts the fluid 55 that was previously supplied to theapplication end of motor M1, and the energization of valve F1 admitsiluid to the restoring end of this motor. Piston 5 of motor M1 thereforemoves to its lefthand position, thus restoring the braking bars of 60the car retarder A1 to their nonbraking positions. When piston 5 ofmotor M1 reaches its extreme left-hand position, contact G1 opens anddeenergizes the valves E1 and F1. In similar manner, the energization ofthe valve E2 exhausts 65 the fluid pressure that was previously suppliedto the application end of motor M2, While the energization of valve F2admits fluid pressure to the restoringend of motor M2. Piston 5 of motorM2 therefore moves toits extreme left-hand posi- 70 tion, and restoresthe braking bars of the car retarder A2 to their non-braking positions.When piston .5 of motor M2 reaches its extreme lefthand position,contact G2 opens and interrupts the previously described circuits forthe valves 75 E2 and F2, so that these valves nowbecome deenergized.Lever LM may now vberestorecl to its normal position, and when thisisdone, all parts Will then be restored to the positions in which theyare shown in the drawing.

It will be apparent from the foregoing, and from an inspection of thedrawing, that the operation of the master controller lever LM to anyposition When the individual controller levers L1 and L2 both occupytheirnormal or N positions energizes the same one or ones of the valvesD1, E1 and F1, and D2, E2 and F2 as would, bel energized if thein-dividual controller levers L1 and L2 Were both moved to positionscorresponding to the position of the master controller lever. It Willalso be apparent from the foregoing that the circuits controlled by themaster lever for energizing any of the valves D1, El and F1 are allcarried over one or more of the contacts 2D, 30, 3l and 32 of the leverL1, and the circuits controlled by the master lever for energizing theValves D2, E2 and F2 are all carried over one or more of the contacts2B, 3U, 3l and 32 of the lever L2, and since the contacts 2U, Bil, 3land 32 of the levers L1 and L2 are closed only when these levers occupytheir normal positions, the movement of any individual controller leveraway from its normal position Will immediately render the control of theassociated car retarder bythe master controller lever ineffective andrestore the control of such retarder to its associated individualcontroller lever. Conversely, When an individual controller lever isreturned to vits N or normal position from some other position, theassociated retarder Will immediately assume a position determined by thesetting of the master controller lever.

Although I have herein shown and described only one form of apparatusfor the control of railway car retarders embodying my invention, it isunderstood that various changes and modications may be made thereinWithin the scope of the appended claims Without departing from thespirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a plurality of car retarders, a plurality of fluidpressure motors, a plurality of indivi-dual controller levers one foreach motor and each having a normal position and a plurality of otherpositions, means controlled by each lever for supplying to a differentone of said motors fluid at a pressure Which depends upon Which one ofsaid other positions the associated lever occupies, a master leverhaving a normal position and a plurality of other positions, and meanscontrolled by said master lever for jointly supplying to each of saidmotors Whosev associated individual controller lever occupies its normalposition iiuid at a pressure which depends upon Which one `of said otherpositions said master lever occupies.

2. In combination, a plurality of car retarders, ari operating motor foreachr retarder, an individual controller lever for each motor and each fhaving a normal position and a plurality of Vlever occupies, said lastnamed means being effective ronly as to those motors Whose associatedindividuallevers are in and remain in their normal positions.

l3. In combination, a plurality of car retarders, an operating Vmotorfor each car retardena plurality of electro-responsive devices for eachmotor for controlling the associated motor, an individual lever foreachmotor for selectively controlling the associated electro-responsivedevices, each said individual lever having a normal position and aplurality of controlling positions, a master lever, and means forselectively controlling by said master lever independently of operationof said `individual levers the electro-responsive control devices forall of those motors Whose individual levers are in their normalposition.

4. In combination, a plurality of car retarders, a fluid pressureoperating motor for each car retarder, a plurality of magnet valves foreach motor for controlling the supply of fluid pressure to, and exhaustof fluid pressure from, the associated motor, an individual manuallyoperable lever for each motor for selectively controlling the associatedvalves, each said individual lever having a normal position and aplurality of controlling positions, a master lever, and means controlledby said master lever for simultaneously selectively controlling thevalves for all of those motors Whose individual levers are in theirnormal position.

5. In combination, a plurality of car retarders, a fluid pressure motorfor operating each car retarder, two magnet valves for each motor onefor controlling the admission of fluid pressure to and the other forcontrolling the exhaust of fluid pressure from the associated motor, anindividual lever for each motor having a normal position and a pluralityof other positions, means controlled by each individual lever forcontrolling the valves for the associated motor in a manner to supplysuch motor With fluid at a pressure which depends upon which one of saidother positions the lever occupies, a master lever having a normalposition and a plurality of other positions, and means controlled bysaid master lever when this lever occupies any one of its otherpositions for selectively controlling the valves for all those motorsWhose individual levers occupy their normal position in a manner tosimultaneously supply such motors With fluid at a pressure which dependsupon which one of said other positions said master lever occupies.

6. In combination, a plurality of car retarders, a fluid pressureoperating motor for each car retarder, a first valve for each motor forcontrolling the admission of fluid pressure to the motor, a second valvefor each motor for controlling the exhaust of fluid pressure from themotor, an lndividual lever for each motor having a normal position and aplurality of other positions, means effective when each individual leveris moved to any one of its other positions for selectively operating thevalves for the associated motor in a manner to supply fluid to suchmotor until the pressure of the fluid builds up to a predetermined valueWhich depends upon the position Which the lever then occupies, and forsubsequently maintaining the pressure in said motor Within predeterminedlimits until the lever is moved to another position, a master leverhaving a normal position and a plurality of other positions, and meanscontrolled by said master lever when this lever is moved to any one ofits other positions forY selectively controlling the valves for eachmotor Whose associated lever occupies its normal position in a manner tosupply `fluid pressure tosuchmotor until the pressure builds up to apre-V determined value which depends upon the position which the masterVlever then occupies, and for subsequently maintaining the pressure insuch motor Within predetermined limits until the master lever issubsequently moved to another position. K

'7. In combination, a plurality of car retarders, a fluid pressure motorfor operating each car retarder, an application magnet for each motoreffective when energized for admitting fluid pressure to the applicationend of said motor to operate said car retarder to its braking position,a restoring magnet for each motor eiective when energized for admittinguid pressure to the restoring end of the associated motor to operatesaid car retarder to its non-braking position, an exhaust magnet foreach motorvelective for exhausting uid pressure from the application endor the restoring end of the associated motor according asV the exhaustmagnet is energized or deenergzed, an individual controlling leverforeach motor for selectively controlling the associated magnets, each saidindividual lever having a normal position and a plurality of controllingpositions, a master lever, and means for selectively controlling by saidmaster lever independently of operation of said individual levers themagnets for all those motors Whose individual levers are in their normalpositions.V

JOHN W. LIVINGSTON.

